Telephone-exchange.



No. 734,386. y PATBNTED JULY 21, 1903.`

w. W.-V WooDRUPF. TELEPHONE EXCHANGE.

' APPLIUATION FILED SEPT. 3, 1902.

N0 MODEL.

ff-.M/yv

UNITED STATES" Patented .my 21, 190e.

"PATENT OFFICE.

WILLIAM w, wooIiRUFF, oir wINcIiEsTR, KE`I`\rIiIoKY-.`

SECIFICATION forming' part of Letters Patent N. 734,386, dated lily 2l, 1902i. Y AApplication filed September 3, 1,902. Serial No. 121,975. `(No model.)

To all when-I, it may concern: l

Be it known that I, WILLIAM W. WOOD- RUFF, a citizen of the United States, residing at Winchester, inthe county of Clark and State of Kentucky,have invented new and use ful Improvements in Telephone-Exchanges, of which the following is a specification.

This invention relates to telephone exchanges,4 and particularly to an apparatus employed in connection with the switchboard of a telephone-exchauge, by means of which the chief operator or other persons in authority may at any time place himself in telephonic communication with the exchange or with any section of the switchboard of the exchange in such manner that he may over-` hear everything taking place in the switch.- board-room. In practice it is found that prompt and' efficient service to the telephone subscribers is seriously impaired by the ex. changeoperators indulging in conversation with each other and with others using the telephones of the system and from other simif lar causes, also that some of the exchange operators are not at all times courteous and polite to those using'the telephones.

The invention has for its object, therefore to provide improved means whereby the chief operator, managen'or the like mayplace him-v self at will in telephonic communication with any desired section of the switchboard, whereby he maylisten to the exchange operator in charge of such section and ascertain whether or not such operator is properly attending to his or her duties, and in such manner thathe will immediately know which operator is remiss or delinquent and without the latter being permitted to know that he or she is under surveillance. f

To these ends my invention consists in the features and in the arrangement, construction, and combination 0f parts hereinafter described, and particularly pointed out in the claims following the description, reference being had to the accompanying drawing, forming'fa part of this specification, wherein is illustrated a telephone-switchboard provided with four sections or panels arranged to be controlled or served by four exchange operators and equipped with my improved apparatus -or attachment for placing the chief with a plurality of annunciator-drops 5 to indicate from which v,of the subscribers telephones the calls are sent in, as usual; 6, 7, 8, and 9, the induction-coils connected with each switchboard-section and the telephone set or the operators receiver'lO and transmitter 11, there being one set for each switchboard panel or section, and 12 the local batteries arranged in circuit with each operators telephone set. The operators receivers 10'are each arranged in circuit with the secondary of the corresponding switchboard induction-coil 9, and the transmitter 1l is arranged in the battery-circuit 1 3, Whichincludes the primary'of said induction-coil.

The switchboard-panels 1, 2,'3,-and 4 are each Y Y provided with a series ofspring-jacks, arranged in the usual manner and not herein shown, for the purpose of establishing telephonic communication between the subscribers. All lthe above parts are constructed and arranged in the usual well-known manner and need not-therefore be further described.

In each of the circuits 13,=whichy includes the primary of the inductionlcoillyand the battery 12, is included the primary vof an auxiliary induction-coil 14, 14, 14", or 14,

there being, of course, one such-auxiliary induction-coil for each switchboard inductioncoil 9, the primaries of the two i'nductioncoils 9 and 14 or 14a 14b 14, the transmitter 11 of the operators telephone set, and the local battery 12, all being therefore in series. Connected to one terminal of the secondary IOO of each of the auxiliary induction-coils is a z` wire 15, common to all of said secondaries,

and it leads and is connected to one terminal of the electromagnet of any selected one of the annunciator-drops 5 of either of the switchboard-sections 1, 2, 3, or 4. From the other terminal of the annunciator-magnet leads a wire 16 to a circuit-selecting mechanism, which will hereinafter be described. From the said selecting mechanism lead wires 17, 18, 19, and 20, which respectively lead and are connected to the other terminals of the auxiliary induction-coils 14, 14, 14", and 14. Connected to the terminals of the annunciator-drop before referred to are terminals of a telephone-circuit 21 22, in which circuit is arranged the chiefs telephone 23, which is of ordinary construction and similar in all respects to an ordinary subscribers telephone. The chiefs telephone 23 may be arranged at any desired point either in the exchange building itself or at a point removed from the exchange at any distanceas, for example, at the chiefs residence. An auxiliary receiver 24, termed, for the Sake of distinguishing it from the .ordinary receiver of the telephone 23, a detector-receiver, is arranged in parallel with the telephone-circuit 21 22--that is to say, the terminals of the circuit 25 are electrically connected to the wires 21 and 22, which may be conveniently accomplished by attaching them to the telephone binding-posts 26 and 27, to which the wires 21 and 22 are attached. From the foregoing it will be apparent to those skilled in the art that if alternations be set up in one of the transmitter-circuits 13 of either of the operators switchboard-sectien-as, for example, by such operator talking or thelike to the neglect of his or her duties-corresponding alternations will be reproduced in the secondary of the auxiliary inductioncoil, and that if the chief closes the circuit in which is included said secondary (by the mechanism hereinafter described) and applies his ear to the detector-receiver 24 he Vcan then hear every sound or word made or uttered by the operator, as will more fully hereinafter appeal'.

The selector mechanism for closing the circuits through the secondaries of the auxiliary induction-coilsis constructed as follows: Fixed to a suitable base 28 are two upright and parallel frames 29, which may conveniently consist of metallic cross-bars 30, in the centers of which latter is journaled the ends of ametallic shaft or arbor 3l. The ends of the several wires 17, 18, 19, and 2O terminate in contacts l, 2a, and 4, arranged near the periphery of one of the circular frames 29, and are insulated therefrom. A metallic switch-lever 32 is fixed at one end on the shat't31, and at its other end is adapted to successively engage the contacts 1, 2, 3, and 4. Attached to the base 28 is one end of a spring-arm34, the other end of which yieldingly bears against one end of, the shaft 31, and to the arm 34 is the end of the wire 16. Each of the frames 29 is provided with two laterally-projecting lugs 35, in which lugs are journaled the ends of a shaft 36, having xed thereon intermediate its ends an armature-lever 37. To the lower end of the lever 37 is attached an armature 38, and the upper end of the said lever is longitudinally slotted, as at 40.

The numeral 41 indicates a pawl, one end of which is adapted to engage the teeth of the ratchet-wheel 33, and the other end thereof is longitudinally slotted, as at 42, and is pivotallyand adj ustablysecured to the slotted end 40 of the armature-lever 37 by a setscrew 43. A coiled spring 44 is attached at one end to the arm ature-lever and at its other end is attached to a projection 45 on one of the lugs 35, said spring operating to retract and hold the armature 38 from its actuatingmagnet.

The numeral 46 indicates an electromagnet, one pole of which is arranged opposite and in proximity to the armature 38. The magnet 46 is included in a circuit 47, which is opened and closed by a switch conveniently arranged on the case of the chiefs telephone 23, and said circuit 47 is arranged in parallel with the local battery of the chiefs telephone. Instead of the switch shown in the drawings a push-button or any other preferred circuit maker and breaker may be employed. By closing the circuit 47 by means of the switch 48 it will be evident that the magnet 46 will be energized and attract the armature 38,and through the medium of the lever 37 and pawl 41 the ratchet-wheel 33 will be turned the distance of one tooth. As there are twice the number of teeth on the ratchet-wheel as there are contacts 1, 2a, 3, and 4, 'and as the latter are arranged at equal distance apart, it will be evident that if the contact-lever 32 is resting midway between two of such contactsas, for example, between the contacts 1 and 2a and that the switch 48 be closedthe contact-lever will be moved into engagement with the contact 2, closing the circuit through the Wire 18 and the secondary of the inductioncoil 14", common return-wire 15, Wire 16, arm 34, shaft 31, and lever 32. When the electromagnet 46 is again energized in the manner described, the contactlever 32 will be moved to a point midway between the contacts 2 and 3, thus breaking the circuit before closed, and when the magnet is once more energized the contact-lever 32 will en- IOO IIS

IIS

gage the contact 3 and will close the circuit in any convenient place in the telephone-exchange building, and should the chiefs telephone 23 be arranged at such distance from the exchange that the telephone-battery will be insufficient to actuate the selector mechanism a relay 49 and battery 50 will be included in the circuit 47.

Let it be assumed thatthe contact-lever 32 is in the position shown in the drawing. Then if the chief closes the switch 48 the magnet 46 will operate through the medium of the mechanism described to move the contact-lever into engagement with the contact 2a. Starting from said contact the circuit will then be completed through the wire 18, the secondary of the auxiliaryinduction-coil 14? of the switchboard-.section 2, and by the common return-wire 15 to the wire 2l of the telephone-circuit, through the detector or auxiliary receiver 24, back bythe wire 22 of the telephone-circuit to the junction of the latter with the wire 16, arm 34, shaft 31, and contact-lever to the contact 2f. It will be obvious that any alternations of current set up in the primary circuit 13, which includes the operators transmitter 7, occasioned by the operator vserving the switchboard-section 2 talking, for example, will setup by induction a corresponding disturbance in the secondary of the auxiliary induction-coil 14h,V

which is included in the-circuit immediately above described, and hence the chief is enabled to hear everything said or sound made by the operator in charge of section 2 of the switchboard. There being no battery ineluded in the described secondary circuit,

when said circuit is completed itwill not aifect. the primary and secondary circuits of the operators telephone set and will occasion no click in the operators receiver or .in any other manner inform such operator that he or she is being listened to by the chief. It is for such reason that the auxiliary or detector receiver 24 is provided, for should the chief attem pt to listen to the operator by taking down the usual hanging receiver of the telephone such action would throw the local telephone-battery into circuit in the usual manner, ringing up the operator and causing the annunciator to fall and indicate that the chief was at his telephone. Furthermore, by using the ordinary receiver of the telephone for vlistening to the operators would have a By operating the switch-lever 48 the chief may suctendency to run the battery down.

cessively listen to all the operators without the latter being aware of the fact. It will be also evident that in order to speak to any one of theoperators it is not necessary that the chief lshould vbe plugged in atthe exchange, as it is merely necessary for the chief by operating the switch-lever 48 to close the circuit through any desired one of the switchboard-sections. Then by taking down his or- .dinary telephone-receiver he is in 'speaking communication with the operatorin chargeof such section. It will also be obvious that should the selector mechanism become inopbeing injured or'hroken from any cause-the operation of the switchboard can in no way be affected.

Having described my invention, what I claim isl. The combination with a telephone-,exchange switchboard and a telephone connected therewith, of a switchboard induction-coil, an auxiliary induction-coil the primary of which is in series with the primary of the switchboard induction-coil and the operators transmitter, a normally open circuit includingtherein the secondary of the auxiliary induction-coil and-connected in parallel with the telephone-circuit, 'and means for closing at will said circuit to place the telephone in circuit with the secondary of the auxiliary induction-coil, substantially as and for the purcircuit including therein the secondary of the auxiliary induction-coil and in parallel with the telephone-circuit, and means controlled from said telephone for opening and closing said circuit at will to put the telephone in circuit with the secondary of the auxiliary induction-coil, substantially as and for the purpose-specified.

3. The combination with a telephone-exchange switchboard, of a telephone connected with said switchboard, a' switchboard induction-coil, an auxiliary induction-coil the primary of which is in series with the primary of the switchboard induction-coil and the operators transmitter, a normally open circuit including therein the secondary of the auxiliary induction-coil and in parallel with the telephone-circuit, an auxiliary receiver arranged in the telephone-circuit, and means controlled from said telephone for closing said circuit to put the auxiliary receiver in circuit with the secondary of the auxiliaryinductioncoil, substantially as and for thev purpose specified.

4. The combination with a telephone-exchange switchboard of a telephone connected v with one of the sections of the switchboard, switchboard induction-coils, one for each switchboard-section, auxiliary inductioncoils, one for each switchboard-section, the primary of each of the said auxiliary induction-coils being in series with the primary of los IZO

the switchboard induction-coil and the operators transmitterin a corresponding section of the switchboard, normally open circuits one' `for each switchboard-section, which include therein the secondary of one of the auxiliary induction-coils and in parallel with the telephone-circuit, selector mechanism for selecting and closing said circuits one at a time, and means for controlling said selector mechanism from the said telephone, substantially as and for the purpose specied.

5. The combination with a telephone-exchange switchboard of a telephone connected with one of the sections of the switchboard, auxiliary induction-coils one for each switchboard-section, which include therein the secondary of one of the auxiliary induction-coils and in parallel with the telephonecricuit, a magneto-electrc device arranged to successively close and open said circuits, a normally open circuit for controlling said magnetoelectric device and leading to said telephone, and a circuit-closer arrangedin proximity to the telephone for opening and closing the circuits for controlling the magneto-electric device, substantially as and for the purpose specified.

6. The combination with a telephone-exchange switchboard, of a telephone connected therewith, a switchboard induction-coil, an auxiliary induction-coil the primary of which is in series with'the primary of the switchboard induction-coil and the operators transmitter, a normally open circuit including therein the secondary of the auxiliary induction-coil and one of the annuuciator-drops of theswitcliboard and connectedinparallelwith the telephone-circuit, and means controlled from said telephone for closing said circuit to put the telephone in circuit with the secondary of the auxiliary induction-coil, substantially as and for the purpose specified.

7. The combination with a telephone-exchange switchboard and a telephone connected therewith, of an auxiliary induction-coil the primary of which is in series with the primary of the switchboard induction-coiLthe operators transmitter and a local battery, a circuit including therein the secondary of the auxiliary induction-coil and connected in parallel with the telephone-circuit,an electro magnetic circuitmaker and breakerforclosingand opening the circuit including the secondary of the auxiliary induction-coil, a circuit connecting the said telephone with the magnet of the circuit maker and breaker, and means arranged in proximity to the telephone for controlling said last-named circuit, substantially as described.

In testimonyV whereof I have hereunto Set my hand in presence of two subscribing witnesses.

WILLIAM W. WOODRUFF.

Witnesses:

H. M. SHAW, J. H. MARTIN. 

